Abstract: Objective To analyze the relationship between polymorphism in CTLA4 gene extron 49 site and promoter 1722 and susceptibility to gastric cancer in Qingdao area. Methods Polymerase chain reaction-restriction fragment length polymorphism and direct sequencing were performed to analyze the genotype of the polymorphism in 49 site and 1722 site. Their correlation with clinicopathological characteristics of gastric cancer was analyzed.
Results The frequency of AG and GG genotype in 49 site in gastric cancer group and atrophic gastritis group were higher than those in the control group（P＜0.05）; and men with gastric cancer carried more AG and GG genotype than women. The frequency of all genotype in 1722 site in gastric cancer and atrophic gastritis group was not significantly different from control group.The single nucleotide polymorphism of promoter 1722 was not associated with gender，age， differentiation and TNM staging of gastric cancer. Conclusion There is a relationship between CTLA-4+49 A／G polymorphism and susceptibility to gastric cancer.